The first issue to decide is who is in charge of directing the wall. In most teams this is the goalkeeper, but you might want to give one of the defenders this responsibility if they are a better leader. On the field, the wall must be organised quickly to avoid being taken by surprise, and this is another advantage of using the goalkeeper; he is always there.
A typical defence at a free kick around the penalty area includes a wall of 2-5 players depending on the angle. There is a player close to the wall whose job is to attack the ball when the kick is taken, and another player to rush out if the ball is played wide to the left of the wall. One defender is marking the space to the right side of the wall, and the remaining defenders are marking behind the wall. For simplicity only two attackers are shown.
The next decision is how many players to put in the wall. If the free-kick is central, then you need 4 or 5 players in the wall. If it is peripheral, then 2 or 3 players will suffice. The first person in the wall should be directly in line with the far post. Once he is lined up, he takes a large step to the side to prevent the ball being curled around the wall. The other players then line up alongside him. A useful tip is to keep a player on the ball until the referee measures the position of the wall. This stops the opposition moving the ball forward and stealing a few metres.
If the free kick is central, then the goalkeeper, needs to decide which side to place the wall. The wall cannot be placed in the middle, because then the shot could be curled into either corner. The wall should cover one side and the goalkeeper the other.
Where to place the tallest players is worth considering, but it depends on whether the person taking the free kick is left or right footed. The opposition need not make this obvious by having two or three players standing over the ball. For example, if the free kick is taken from the right, a right footed player would tend to curl the ball from right to left into the right corner of the goal. Therefore it would be sensible to have the tallest player on the right side of the wall. Now imaging a left footed player taking the free kick. He will tend to curl the ball from left to right. Therefore it is sensible to have the tallest player on the left side of the wall. When the free kick is from the left, the opposite applies.
The best technique for the players in the wall is to stand square to the ball, take one step forward as the ball is kicked, and stand up on their toes. This make the wall as tall as possible. Some teams try jumping, but it leaves a risk of the ball going under the wall.
In the picture, there is a player ready to charge from the left of the wall. He is in line with the back post to provide extra cover for the goalkeeper. It is important that he does not obscure the view of the goalkeeper. An alternative is for the charger to come from a sharper angle.
Notice the player to the right of the wall. His job is to guard that space from any short passes around the wall. Argentina once scored a goal against England when a player moved off the wall into this space, and there was nobody marking him. Even in man-to-man marking, it is important to guard the spaces either side of the wall.
The other players need to mark any attackers, particularly passes to the far post, and they need to be alert for rebounds.
